The two were initially detained on April 8, but this information has just been revealed.

Russian authorities in Istanbul reportedly learned “about the detention on Sunday, and the consul met with them on the same day.”

On Monday, the Russian consul took part in the preliminary hearings, but wasn’t allowed to stay for the main hearing.

“The detained told us they arrived [in Turkey] as tourists, and deny the accusations against them,” the Russian general consul added.

“Regarding the reasons for the detention, the Turkish authorities didn’t tell us anything, citing alleged security concerns,” Aleksey Chekmaryov, from the Russian diplomatic mission, said, as cited by Interfax.

Abdulvakhid Edelgireev was killed on November 1, 2015, in his car, next to his Istanbul home. Turkish investigators discovered that the vehicle had been rented 20 days before the killing by a Russian national, Aleksandr Nasyrov.

Edelgireev was known as the administrator of the ‘Kavkaz Center’ website, recognized as extremist in Russia. His father-in-law Isa Umarov is a member of the terrorist group ‘Imarat Kavkaz’, which was behind the deadly 2010 metro bombing in Moscow, among other terror acts.